TREVOR VERTUCA leads EZRA THE ELF and a WARRIOR into a sewer tunnel. He is fully into their fantasy role-playing game even though his friends want to quit. It's not long before Trevor's buddies flee the tunnel. Trevor sighs. He apologizes to the princess that spooked his friends. Of course, she'll need to deduct points from their team because they broke character. As he gets closer, he realizes this woman is not part of the game. It's a decaying corpse!
At Booth's apartment, BOOTH opens the door for BRENNAN. She immediately notices that he's injured his back. Booth asks for an adjustment. Brennan is reluctant to help. She is not a medical doctor and this problem may require one. Booth won't take no for an answer. Last time this happened, Brennan's adjustment worked like a charm. Brennan puts her "magic knuckles" to work but Booth's pain gets worse...
At the lab, Brennan tells ANGELA that Booth may have a herniated disk. She'll have to see the X-rays to know for sure. For now, Booth is on bed rest. Enter AGENT PAYTON PEROTTA. Brennan is less than happy to see Perotta, but she requested her as Booth's substitute. "The variables involved in breaking in a new person outweigh the benefit of possibly finding a better investigator." The remains wait on the Forensic Platform. Displeased that she wasn't invited to the scene, Brennan approaches the body. COLIN FISHER reports that the victim is female, aged 25 to 29 years. Her face has been severely damaged around the mandible. Brennan releases the flesh to CAM and hurries off, ignoring Perotta. Cam notices something unusual about the flesh on the victim's hand. Perotta steps in. She shines an ALS pointer on the hand, revealing a blacklight-sensitive stamp.
In Angela's Office, Angela shows Brennan the UV stamp. She hasn't been able to match it to area bars or clubs. Fisher barges in with a confession: he is a geek. However, this means he has an idea of where the victim got her hand stamp. Fisher believes she worked as a booth babe at ImagiCon, a convention for fans of video games, comic books and more. Angela pulls up the website. The ImagiCon logo matches the UV hand stamp. Brennan spots a photograph of girl wearing the same dress found on the corpse. Could this be the victim?
At ImagiCon, Perotta and Brennan observe the many costumed attendees. They approach a booth advertising the Grimoire 3.0 and cut to the front of a line of fans waiting to take their picture with SHINY KOPINSKY, the booth babe. Shiny confirms that the victim is KENDRA KIM, her fellow booth babe. She hasn't been to work in a few days. Shiny figured that she'd been fired. Kendra had a bad attitude. Apparently, Kendra was about to come into some money but she wouldn't say where the money was coming from. Shiny followed her once, but all she saw was Kendra talking to someone at another booth: Kroon the Blacksmith.
Perotta and Brennan speak to KROON THE BLACKSMITH, also known as Peter Kroon. He can't quite remember Kendra's name, but he does know one thing: she was the girl with Excalibur. Kendra was in possession of a rare prop movie sword. It was worth tens of thousands of dollars, and hadn't been seen in 20 years. Kendra told Peter she'd gotten it from her family, but he could tell that was a lie. In any case, he suggested she list it for sale at the upcoming ImagiCon auction.
At the lab, Fisher reports that the damage to the body is confined to the skull. HODGINS also has news. The victim died about 72 hours ago. He found soil and Virginia nailwort under the victim's fingernails. Before he leaves, Hodgins and Fisher argue about who is more depressed over their recent breakups. Fisher wins.
In Brennan's office, Brennan calls Booth to check in. Through the painkillers, he tells Brennan that he may have a herniation. Booth puts Brennan on hold to take a call from Perotta. Perotta tells Booth they have located the victim's father. Brennan chimes in. Booth accidentally hit "conference" instead of "hold." Perotta listens as Booth insists he will be at the interview while Brennan insists he will stay home and rest. Perotta feels a headache coming on.
At the FBI, Perotta questions BRUCE KIM, the victim's father. Booth attends the interview...via webcam. Mr. Kim explains that all of Kendra's paychecks were sent to him. He was handling her money until she paid off the mortgage on the condo he bought for her. However, he doesn't know anything about a sword. Perotta closes the laptop when Booth's comments become distracting. Mr. Kim agrees to let Perotta see Kendra's condo.
Brennan and Perotta arrive to inspect Kendra's condo. The place is completely ripped apart. Chairs are overturned, couch cushions are ripped open, everything is in disarray. Someone was looking for the sword.
FBI techs comb the condo as Perotta supervises. The search turns up a cracked answering machine and a pair of sneakers that Hodgins will analyze at the lab. He can tell there are insects, soil and blood on the sneakers.
At the lab, Brennan and Fisher look closely at the damage to the victim's jaw. "The force radiated symmetrically from the center of her mouth," Brennan concludes, after hearing Fisher's findings. Brennan has no idea what weapon could cause this damage, which depresses Fisher.
In the Autopsy Room, Hodgins tells Cam that the blood on the victim's sneakers belongs to an American Toad. This type of toad can only be found in one location in the area. The victim was near the Potomac sometime before her death. The soil underneath her fingernails confirms this theory. Hodgins believes Kendra went there to bury something.
At the FBI, Perotta shares the message recovered from the victim's answering machine with Sweets. "I don't know who you think you're fooling, little princess, but you're playing with a woman who gets what she wants. You've got three days. I want that sword." She asks Sweets if he can profile the mysterious woman from her message. Sweets believes that the woman thinks Kendra is just a "girl," meaning a child. He suggests the woman has already tried to take this sword from someone else, perhaps a grown man. Perotta points out that the victim did bring the sword to a male auctioneer...
At the ImagiCon Auction Hall, Perotta and Sweets question CARL DERF, the auctioneer. He assures them that his auction is completely by the book, but when Perotta mentions illegal pre-bidding, he gets nervous. Sweets can see that Carl Derf is lying. Carl confesses that he gave Kendra's contact information to a woman named Valerie Daniels, a medieval weapons collector. He confirms that it is her voice on Kendra's answering machine.
Sweets and Perotta sit with VALEIE DANIELS in the Interrogation Room. She collects weapons to spite her parents, who think it is a waste of her trust fund. She stops propositioning Sweets long enough to give Perotta her alibi: she was at a party. She slept with one of the guests so they can check with him. Perotta wants to know why Valerie destroyed Kendra's condo. Valerie doesn't know anything about that. All she knows is what Kendra told her. On the first day of ImagiCon, someone dressed as a black knight simply handed the sword to Kendra. Valerie has spent her whole life collecting weapons. Kendra didn't deserve that precious item, but Valerie didn't kill her.
Meanwhile, on the roadside near the Potomac, Angela and Hodgins search through patches of grass, looking for what Kendra might have buried. Hodgins finds something with his metal detector. He begins to dig. Angela helps, and before long they uncover a sword wrapped in plastic. Hodgins raises it above his head and proclaims, "I am the once and future king!" Angela rolls her eyes.
At the lab, Hodgins fights an invisible foe with the sword. Sweets also wants a turn with the sword. He observes that the team now has what the killer desires most. He will try and retrieve it. Sweets has a plan. They should set a trap for the killer. They will put the sword up for auction, but Sweets will outbid whoever wants it most, hopefully inciting the killer to reveal himself. He volunteers Fisher to run the camera and be his partner inside.
At the Auction Hall, Fisher is dressed for his undercover role. He films everything while Brennan and Perotta watch backstage via laptop. Peter Kroon and Valerie Daniels are both present. Brennan notices someone dressed as a black knight. Valerie did say that a knight gave the sword to Kendra. It's time for the auction. Sweets sits in the crowd dressed as a space commander. Valerie sits right next to Fisher. The bidding begins and, at first, Valerie and Sweets battle for the sword. However, a man with an English accent outbids them both. Everyone turns to look. Now the battle is between this mysterious man and Sweets. The competition heats up but Sweets makes the winning bid for half a million dollars. All the attendees congratulate him, while Perotta pulls aside the mysterious bidder.
BADGLEY MORMONT isn't happy to be stopped by Perotta. He has to catch a flight. He represents a group known as the Arthurian Consortium. They collect Camelot related items. He was bidding on their behalf. Carl Derf, high on adrenaline from the auction, rushes into the room. He assures Perotta no one knew the auction was faked. Badgley is not pleased to hear this. He threatens to sue.
Sweets drives Brennan home from the auction. He is thrilled that he won the auction item, even though it was staged. As Sweets gushes, another car runs him off the road. Sweets and Brennan crash. A black knight approaches the car. He grabs the sword, but Brennan goes after him. They fight and she reclaims the sword, forcing him to retreat. Sweets tells her she did a good job, before collapsing on the steering wheel.
After hearing about Brennan's car accident, Booth painfully tries to get up so that he can see her. On the phone, Brennan assures him that she is fine. Booth pretends to respect Brennan's wishes and stay at home, but the real reason he's staying home is that he simply can't move. Brennan puts Perotta on the phone. Booth instructs Perotta to protect Brennan. He then downs some Vicodin and turns on cartoons.
Hodgins analyzes paint chips left on Sweets' car from the crash. While the computer looks for a match, Angela shares her concern. Brennan and Sweets could have been killed. They shouldn't be putting themselves at risk. Hodgins agrees, but admits no one can change Brennan. The computer has match: a 90's Ford Explorer.
On the Forensic Platform, Cam tells Brennan there is blood on the sword. She wounded her assailant. There are also various nicks and scratches on the blade. The knight wasn't wearing armor, so what could have caused them? Sweets enters to thank Brennan for saving his life. He likens her to Xena and wants to call her "Bones" as a sign of their new closeness. Brennan shoots him down.
At the FBI, Perotta has a room full of knights. She talks to Cam on the phone and explains that none of them drive a Ford Explorer. Cam suggests she round up more knights. Fisher rushes into the Autopsy Room. He knows what the murder weapon is, and he has one with him. It's called the "Pear of Anguish." He noticed it in Valerie's collection of torture devices when he slept with her last night. Cam is none too pleased to hear that he canoodled with a suspect. "This particular Pear of Anguish was to be inserted in either the vagina or anus. There are larger ones for the mouth," Fisher describes. He demonstrates the weapon on a skull. It is easily crushed. Cam is sickened in many ways. She has to discipline Fisher for getting involved with a suspect.
At the lab, Cam makes Fisher sit in the corner while she, Brennan and Hodgins discuss the case. They are still having trouble determining what caused the marks on the sword. Fisher chimes in. The sword may have struck chain mail. Brennan instructs Hodgins to get out his metal detector.
At the scene of the crash, Hodgins searches with his metal detector. Brennan shares her theory. Perhaps her attack on the knight loosened some of his chain mail. Sure enough, the pair locates a few links of chain mail on the ground along with parts of Sweets' car.
At the lab, Hodgins reports that the chain mail is an extremely good replica. Cam wonders if he can trace the manufacturer. Hodgins says he already handed that task off to Fisher, trying to help him gain favor with Cam again. Fisher prefaces his report by promising never to have sex again. Cam decides he doesn't have to go that far, but he will have to be more discreet. She looks at Fisher's report. Peter Kroon, the blacksmith, manufactures his own chain mail.
At the FBI, Kroon sits in the Interrogation Room, his arm in a sling. Perotta and Brennan have all the evidence they need to prove that he committed this murder. His car ran Sweets off the road. His blood was on the sword. His chain mail was at the scene of the crash. Even his arm is consistent with the injury Brennan gave to her attacker. They just don't know why he did it. Sweets has the answer. In the Observation Room, he reads one of Kroon's poems to Brennan, who repeats it. "What is a man without his love? If love turn his back on thee, it is as a hearth with no fire. 'Tis best to slay the false heart, to waken from the dream that is life, than live dark hearted in a dark world." Kroon gave his most precious possession to Kendra as a token of love, and she turned around and tried to sell it for material gain. Thus, he murdered her.
At Booth's apartment, Brennan sums up the case for him while looking at his X-rays. Brennan realizes that Booth simply has a misalignment. He was misdiagnosed. She can fix his back right now. Booth is understandably reluctant. As Brennan gets into position behind him, there is a knock at the door. Booth calls for the visitor to come in. Perotta enters to find Booth and Brennan in an interesting position. Brennan immediately says she is done. Booth is fine and she has to go. Perotta, a little embarrassed, also makes a quick exit. Booth stands alone in his apartment, not quite believing his back is fixed, afraid to move.